You could email openreach and ask them (the email address on this site somewhere). As Mr Saffon said your cab is probably uneconomical to upgrade. I'm in that category, quite annoying as all the other cabs in the area (apart from 2 other small cabs) are getting upgraded.
You could write to your local councillor or MP to see if they can do anything. The reality is money talks, if the take up for BB/properties connected in your cab are low chances are you aren't getting fibre. Sadly for me Virgin are in my area so looks as if there's no chance of it being upgraded for a long while. Pity really as I didn't choose to be connected to a small cab.
Local campaigning to get locals to register interest/contact openreach/mp etc might show someone somewhere looking at a spreadsheet that there is interest. I'm probably going to try this, though chances are it'll fail as well (forever the optimist!).
Current on Zen, getting around 5mb.
Exchange is Fibre enabled, street cab not economically viable to upgrade.
Could get V*rgin, but I'd rather not.